Vehicle-tire.



NITED STATES PATENT OFFICE.

HOWARD MALCOLM DU BOIS, OF ASHBOURNE, PENNSYLVANIA.

VEHICLE-TIRE.

SPECIFICATION forming part of Letters Patent No. 637,717, dated November21, 1899.

Application filed May 11 1899. serial No. 716,456. (No model.)

To all whom it may concern:

Be it known that I, HOWARD MALCOLM DU BOIS, a citizen of the UnitedStates, residing at Ashbourne, Montgomery county, in the State ofPennsylvania, haveinvented new and useful Improvements in Metal Tiresand in Rubber Tires for Wheels,'of which the following is aspecification. I

The object of this invention is to construct tires for wheels soproportioned as to accord with the mechanical principles of the vehicle,and thus avoid unnecessary strain upon the Wheel, diminish theresistance to the motion of the wheel, and reduce the Wear and strainupon the rubber tire while in action.

The accompanying drawings illustrate the invention. I Figure Iis an edgeview of the wheel. Fig. II is a cross'section of the wooden felly, thegrooved metal tire, and the rubber tire. Fig. III is a top edge view oftwo Wheels of a vehicle; Fig. IV is a front edge view of two wheels of avehicle.

To fully understand the scope of this invention, a knowledge of themechanical principles observed in the construction of vehicles isnecessary. Vehicles are so constructed that the friction of the wheel isreduced to a minimum and also so that the wheels and tires may be strongto resist the opposing forces. To accomplish this, the axles are setwith what is called in the art gatherthat is to say, the axles of thewheels are inclined slightly forward from the collar to the point, sothat the distance between the wheels is less in front than back. (SeeFig. Ill.) The wheel when in motion is thus caused to press againstthecollar of the axle, the draft is brought to aflxed point, and themotion of the wheel made steady. The axles are also set with what iscalled swing. To accomplish this, the spokes are inclined inwardly fromthe felly to the hub, so that the Wheels from an outer point of view areconcave in form or dished.-

The axles are inclined downward to an extent equaling the dish of thewheel. (See Fig. IV.)

The plumb spoke is thus secnredthat is, the spoke which supports theload and is directly in the line of Weight stands plumb and the weightis thrown upon the center of the box,,which is secured in the hub of therevolving wheel.

The rubber tires heretofore made have been so formed that the apex ofthe tire, which first comes in contact with the pavement, is at a pointperpendicular to the center of the'channel or tire. When sucha rubbertireis placed on the wheels of a vehicle constructed in the way abovementioned, so that the wheels will have sufficient swing to secure aplumb spoke and sufficient gather to reduce the draft to a minimum, theweight of the load in the vehicle flattens the rubber at the point ofcontact, and as the wheel revolves forward the rubber is forced inwardover the edge of the channel, thus changing the line of weight from thecenter of the box of the wheel inwardly toward the collar of the axle.When a vehicle turns a corner, the wheels which describe the outercircle are whirled about with great centrifugal force, the weight of theload shifts outward, and the rubber tire, which clings to the pavement,is pushed inwardly, while the wheels which describe the inner circle areso acted upon by the momentum and the shifting of the center of gravityof the vehicle that the rubber tires are forced outward. When the rubberflows outward over the flange, the force of the lever, the flange beingthe fulcrum, is exerted against the dish of the wheel in a directionopposite to that which the wheel is made to resist, thus causing thespokes to weaken, and at the same time causing an extraordinary strainupon the inner retaining-wire. To overcome these dlfliculties, I haveconstructed a tire which is supported, strengthened, and shaped asfollows: About the wheel is fastened a grooved metal tire A, withflangesinclined at any angle desirable. The edges of the flanges areround to prevent abrasion of the rubber. The inner flange B is longerthan the outer flange 0. Into the groove of the metal tire the rubbertire D is fitted. It is held in place within the groove by two wires Gand F. More wires may be used, if desired. The wires are drawn .throughholes extending throughout the length of the rubber tire. The outer wireG is preferably equidistant from the base and flange of the metal tire,whereas the inner wire F is more distant from the base of the metal tirethan the wire G. The wires are se-' cured and tightened by welding,twisting, or other convenient method. The rubber tire too D is concavefrom its apex to the point of contact with the long inner flange, whileit excessive dish.

is slightly S-shaped from the apex to the point of contact with theouter flange O. The apex of the tire is 'at the point H, which is inwardfrom the lineX, erected perpendicularto the centerof the metal tireA.Thus the greater bulk of the rubber tire is inward from theperpendicular line X. The rubber tire must withstand three forces-first,the upwardpushingforce against the line of weight; second,theinward-pushingsidewise force caused by the gather of' the wheels, and,third, the outward-pushing sidewise force caused when the inner wheelsof the vehicle turn a corner.

The inward force exerted because of the gather of the wheel is resistedby the long inner flange B of themetal channel, which prevents therubber from flowing inward over thepermits freer movement of themolecules of .rubber. When the metal tire is placed about the wheel, itis expanded by heat. Because of the greater weight of the inner edge ofthe metal tire when the'metal is cooled a greater pressure is exertedupon the'inner edge of the wooden felly of the wheel thanupon the outeredge. This restrains the wheel from The tire thus constructed andprotected is confined within the metal flanges and never forced betweenthe flang'es and the pavement. Thus unnecessary dragging of the rubberand resistance to the motion are prevented. Such a tire is in accordwith the principles of plumb spoke and gather,

which cause the force exerted against the inner metal flange to beopposed by the plumb spoke of the wheel. Furthermore, it prevents theline of weight from moving from the center of the box of the wheel, thusavoiding unnecessary strain and friction.

What I claim as my invention, and desire to secure by Letters Patent,is-

1'. A rubber tire for a vehicle, fitted into a grQove or flanged metaltire in which the inner flange is longer than the outerflange,so shapedthat the part resting upon ther oa d-bed shall have its center inwardfrom the center of the metal tire and kept in place by means of wireswhich are tightened about the wheel through holes in the rubber, eachhole being in a different horizontal plane from the base of the metaltire, substantially as hereinbefore described.

2. A rubber tire so shaped that the greater bulk of therubber is in wardfrom a line erected perpendicular to the center of the plane of themetal channel upon which the tire rests, substantially as hereinbeforedescribed.

3. A vehicle-wheel with a flanged metal tire the flange inward towardthe vehicle being longer than the outer flange, so that a rubber tire,shaped with the greater bulk of the rubber inward from a planeperpendicular to the central point of the metal tire, when fastened 7 5in'the metal channel, will bear against the longer flange, substantiallyas shown and for the purposes specified". it

4. A vehicle-wheel with a flanged metal tire in which the flange inwardtoward the vehicle is heavier than the outer flange, so that a rubbertire, shaped with the greater bulk of the rubber inward from a planeperpendicular to the center of the metal tire, will bear against theheavier flange, substantially as shown,

for-the purposes specified.

5. A rubber tire having holes throughout its length through whichretaining-wires extend, each in a different horizontal plane,substantially as shown for the purpose specified. 9o

6. A vehicle-wheel with a flanged metal tire, in which the flange inwardtoward the vehicle is longer and heavier than the outer flange,

into which metal tire is fitted a rubber tire, shaped with the greaterbulk of the rubber inward from a plane perpendicular to the center ofthe metal tire, so that the rubber will bear against the long heavyflange, the rubber being held in place by two or more wires extendingthrough the rubberabout the wheel, 10o

substantially as described and for the purpose specified.

In testimony whereof Iaffix my signature in thepresence of twowitnesses.

HOWARD MALCOLM DU BOIS. Witnesses:

DAVID C. BENNETT, J r.,

CHARLES W. MoOANDLEss.

